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| author | H.J. Lu <hjl.tools@gmail.com> | 2024-02-25 16:03:26 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2024-02-28 13:40:55 -0800 |
| commit | a1735e0aa858f0c8b15e5ee9975bff4279423680 (patch) | |
| tree | ac5f95008a2ddf782df051bfd1b2b14b7e583c66 /elf | |
| parent | 8c7c188d62d76acda1b273b0d4d9c3b32983b28d (diff) | |
| download | glibc-a1735e0aa858f0c8b15e5ee9975bff4279423680.zip glibc-a1735e0aa858f0c8b15e5ee9975bff4279423680.tar.gz glibc-a1735e0aa858f0c8b15e5ee9975bff4279423680.tar.bz2 | |
x86_64: Suppress false positive valgrind error
When strcmp-avx2.S is used as the default, elf/tst-valgrind-smoke fails
with
==1272761== Conditional jump or move depends on uninitialised value(s)
==1272761== at 0x4022C98: strcmp (strcmp-avx2.S:462)
==1272761== by 0x400B05B: _dl_name_match_p (dl-misc.c:75)
==1272761== by 0x40085F3: _dl_map_object (dl-load.c:1966)
==1272761== by 0x401AEA4: map_doit (rtld.c:644)
==1272761== by 0x4001488: _dl_catch_exception (dl-catch.c:237)
==1272761== by 0x40015AE: _dl_catch_error (dl-catch.c:256)
==1272761== by 0x401B38F: do_preload (rtld.c:816)
==1272761== by 0x401C116: handle_preload_list (rtld.c:892)
==1272761== by 0x401EDF5: dl_main (rtld.c:1842)
==1272761== by 0x401A79E: _dl_sysdep_start (dl-sysdep.c:140)
==1272761== by 0x401BEEE: _dl_start_final (rtld.c:494)
==1272761== by 0x401BEEE: _dl_start (rtld.c:581)
==1272761== by 0x401AD87: ??? (in */elf/ld.so)
The assembly codes are:
0x0000000004022c80 <+144>: vmovdqu 0x20(%rdi),%ymm0
0x0000000004022c85 <+149>: vpcmpeqb 0x20(%rsi),%ymm0,%ymm1
0x0000000004022c8a <+154>: vpcmpeqb %ymm0,%ymm15,%ymm2
0x0000000004022c8e <+158>: vpandn %ymm1,%ymm2,%ymm1
0x0000000004022c92 <+162>: vpmovmskb %ymm1,%ecx
0x0000000004022c96 <+166>: inc %ecx
=> 0x0000000004022c98 <+168>: jne 0x4022c32 <strcmp+66>
strcmp-avx2.S has 32-byte vector loads of strings which are shorter than
32 bytes:
(gdb) p (char *) ($rdi + 0x20)
$6 = 0x1ffeffea20 "memcheck-amd64-linux.so"
(gdb) p (char *) ($rsi + 0x20)
$7 = 0x4832640 "core-amd64-linux.so"
(gdb) call (int) strlen ((char *) ($rsi + 0x20))
$8 = 19
(gdb) call (int) strlen ((char *) ($rdi + 0x20))
$9 = 23
(gdb)
It triggers the valgrind error. The above code is safe since the loads
don't cross the page boundary. Update tst-valgrind-smoke.sh to accept
an optional suppression file and pass a suppression file to valgrind when
strcmp-avx2.S is the default implementation of strcmp.
Reviewed-by: Sunil K Pandey <skpgkp2@gmail.com>
Diffstat (limited to 'elf')
| -rw-r--r-- | elf/Makefile | 3 | ||||
| -rw-r--r-- | elf/tst-valgrind-smoke.sh | 5 |
2 files changed, 5 insertions, 3 deletions
diff --git a/elf/Makefile b/elf/Makefile index 02dc476..f0439ef 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -617,7 +617,8 @@ tests-special += $(objpfx)tst-valgrind-smoke.out endif $(objpfx)tst-valgrind-smoke.out: tst-valgrind-smoke.sh $(objpfx)ld.so $(objpfx)valgrind-test $(SHELL) $< $(objpfx)ld.so $(rtlddir)/$(rtld-installed-name) '$(test-wrapper-env)' \ - '$(run-program-env)' '$(rpath-link)' $(objpfx)valgrind-test > $@; $(evaluate-test) + '$(run-program-env)' '$(rpath-link)' $(objpfx)valgrind-test \ + '$(valgrind-suppressions-tst-valgrind-smoke)' > $@; $(evaluate-test) tests += $(tests-execstack-$(have-z-execstack)) ifeq ($(run-built-tests),yes) diff --git a/elf/tst-valgrind-smoke.sh b/elf/tst-valgrind-smoke.sh index e33b2fa..7d0ceac 100644 --- a/elf/tst-valgrind-smoke.sh +++ b/elf/tst-valgrind-smoke.sh @@ -25,6 +25,7 @@ test_wrapper_env="$3" run_program_env="$4" library_path="$5" test_prog="$6" +valgrind_suppressions="$7" # Test whether valgrind is available in the test # environment. If not, skip the test. @@ -34,7 +35,7 @@ ${test_wrapper_env} ${run_program_env} \ # Test valgrind works with the system ld.so in the test environment /bin/sh -c \ "${test_wrapper_env} ${run_program_env} \ - valgrind -q --error-exitcode=1 \ + valgrind -q --error-exitcode=1 ${valgrind_suppressions} \ ${system_rtld} /bin/echo ${system_rtld}" || exit 77 # Finally the actual test inside the test environment, @@ -42,5 +43,5 @@ ${test_wrapper_env} ${run_program_env} \ # the smoke test under valgrind. /bin/sh -c \ "${test_wrapper_env} ${run_program_env} \ - valgrind -q --error-exitcode=1 \ + valgrind -q --error-exitcode=1 ${valgrind_suppressions} \ ${rtld} --library-path ${library_path} ${test_prog} ${rtld}" |